RFR (S) 8193622: JFR test TestUnloadingEventClass.java times out intermittently

[coleen.phillimore at oracle.com]

On 12/19/17 10:40 AM, Markus Gronlund wrote:
> Hi Coleen,
>
> Line 850 says: // Only constant pool entries have C heap memory to free.
>
> But, with the change, there is an additional else clause that seems to process klasses.
>
> Maybe remove the comment?

Yes, I meant to remove that comment.  Thanks.
>
> Also:
>
> Is the metadata is_klass() check sufficient in allowing for a direct downcast to InstanceKlass* (not Klass*?). Maybe only InstanceKlass'es will ever be on the deallocation_list in this context?

Yes, only InstanceKlass will be on the deallocate list.  I should change 
this and free_deallocate_list with a future RFE.  I used is_klass() 
because that's what free_deallocate_list had.

> In addition:
>
>   857        // Remove the class so unloading events aren't triggered for
>   858       // this class (scratch or error class) in do_unloading().
>   859       remove_class(ik);
>
> Does this not remove every klass? Not just a scratch or an error klass?

Only every Klass that is on the deallocate list, which are the scratch 
and error klass.   The other classes aren't on this.

Thanks!
Coleen
> Thanks
> Markus
>
>
> -----Original Message-----
> From: Coleen Phillimore
> Sent: den 19 december 2017 12:43
> To: hotspot-runtime-dev at openjdk.java.net runtime <hotspot-runtime-dev at openjdk.java.net>
> Subject: RFR (S) 8193622: JFR test TestUnloadingEventClass.java times out intermittently
>
> Summary: Previous change was leaving scratch classes on CLD::_klasses list which are reported to tracing
>
> Tested with assert in tracing code and failed test, and mach4 tier1-5.
>
> open webrev at http://cr.openjdk.java.net/~coleenp/8193622.01/webrev
> bug link https://bugs.openjdk.java.net/browse/JDK-8193622
>
> This change is relative to jdk/hs repository but will be moved to
> jdk/jdk10 once the jdk/hs snapshot is integrated.
>
> Thanks,
> Coleen